Sewing machine



May 5, 1925.

J. A. GRor-:BLI n SEWING MACHINE Filed July 16, 1925 A 2 Sheets-Sheet 2 35% M1/@Homey part of the head and-attachments of a sew-` `l?attnited May 5, V1925.

onrrensrares insana raten rin.

, JOSEPH AVGROEBLI, O-F NEWT YRK, .'L\T, Y.

SEWING MAGHNE.

'Applicatioirlcd July 16,

`proveniente in Sewing'Machines, of which the following` is a specification.

My invention relates to sewing` machines, and its principal object is to obtain increased accuracy in` the `formation of loop stitches by snugging up the thread under the barbof `the needle before the needle draws it down throughthe loop, my improvements being` particularly directed to novel meijrnsivhereby theslacl of the thread is taken `up at the proper moment, after which the normal tension of the thread is reestablished.

y ln the drawings I have illustrated my improvements `as applied to a bead-sewing machine; and Fig. l is a side elevation of ing machine provided with my improvements, the bead separator' and looper being, however, in section; Fig. 2 is a top view, on an enlarged scale, of the thread reel and talre'up mechanism, taken as on `the line` E-Q ofFig. l looking,I down; Fig. o is an elevation of the reel holder and reel, taken asloolri-ng to the left on Fig. 2; litige. li, 5, and ('3 are views illustrating successive positionsof` the taire-up control as itrevolves around its actuating cam; Figs. Y, S andi) illustrate the positions of the threads and needle at the points in the formation of a stitch corresponding respectively with the positions of the mechanism illustrated `in Figs. t, 5, and 6; and Fig. l0 is a detail. i

The same parts are designated by c0rre- `sponding reference numerals in all the figures.`

fr type of machine to which my improvements may be applied is shown in .my liet.

ters atentllo. iylfltntl, of lfebruary 20, i923; and the details of the embodimei'it oi': `my improved mechanism in such a machine will be `readily understood when it is noted that tubes 38 and 53 of my present application correspond to the elements similarly numbered in my aforesaid patent, and are supported and actuated in a similar manner;`that similar i needle actuating mech anism may be employed; and that the bead vthread maybe supplied by means like those n illustrated in said patent.

`lnr operation the needle 1 produces, with 1923. Serial No, 651,757.

the stitching thread 2, a loop stitch, the stitching` thread beingl preferably thrown around the bead thread 3 by the looper t, during the formation of the stitch, to attach that thread and its beads in proper position on the. fabric. The l'ooper fl. is carried by and revolves with the tube 38; while the bead separator shown is of the 'jaivcd type, and is adapted to release a bead with each revolution of the separator. The details of construction of this separator are the subject of a separate application, so l:

`will not describe them further herein.

The stitching,` thread reel (i is supported by and also revolves with, the tube 38, be ing1 connected therewith by a suitable bracket 7, upon which it is` mounted above asprin;l 8 and a ratchet Wheel 9 to which it is connected by a pin i0. .lhe reci turns on a spindle 1i, being detachably held in place by a movable arm lit carried by a shaft 15, the arm lll: being normally held doivn above the reel by a coiled spring 16, which per mits it, however, to 'be raised and swung around sufiiciently to clear the spindle il andthe reel 6. i

To the tube e?) is 'fas-tened a collar 2() pro vided with a cani racel on its lmver side,

`against which travels the end of arm fastened upon a shaft 23, Whiclris rotatably mounted in a bearing;v on the bracket l2.

The arm 22 has an extension or` branch 2l, between which and the bracket l2 stretched a` spring Q5, which normally keeps bracket 7 is stretched a spring; 323 which,`

tends to throw the pawl 3l into contact `with the ratchet wheel 9. This movement of the pawl, however, is controlied through another' arm 3ft, carried by the shaft S0, the free endfl of which travels against the face of a. cam collar 36, fastened, as by a set screw 37, to the shaft 53, and provided With a depressed portion 3) into which the end 35 of the arm 841 Will enter, at each revolu` tion of the bracket 7, `so as to allow the pawl 31 to engage with the teeth of the Wheel 9 and arrest the rotation of the reel.

This locking of the reel takes place, preferably, just before the end of the arm 22 reaches the recess ill the cam collar 20; and the ratchet wlleel is released from the pawl, preferably, just as the end of the arln 22 clears the recess in the caln race.

ln operation, the stitching thread is drawn oil" its reel, under a llornlal tension, by the needle and the movement of the fabric, during the preliminary portion of the stitch forming' cycle and until the needle descending` and the looper has swung; around behind the needle, for instance, as indicated in Fie'. S. lut, preferably, ]ust before this position is reached the rotation ot' the tube 38 and the braclret i' around the tube 53 brings the end 35 of the aria 34- to the recess 39 in the cani collar 36, allowing; the spring: -ll to rock the shatt 30, causing' the pawl 3l to @usage the ratchet wheel 9, stopping' the rotation ot the reel 6.

rPhe continued rotation of the bracket 7 then brings the free end of the arm 22 to the recess in the collar 90, allowing the arnl to rie, and to f gire a Quick `ierk upwards against the thread 2 which passes over the arm on its course to the cllannel between tubes 3S and 5S through wllich it travels down to the looper and needle. The reel being;- held by the braking mechanism, embracing the ratchet wheel and pawl already described, can not turn to yield lnore thread; and the slack of the thread betw'een the reel and the fabric will be taken up by the upward movement of the arm 22, seras to draw the thread more or less taught and to snug it around the shank of the needle l below its barb, preventing the bal'b from slipping past the thread and dropping' the stitcll. As the continuation of the stitch cycle requires ll'lorethread, this is provided for by the gradual lor-:cling` of the arm 22 by the longr slope of the cam race, as the arm travels past it, the thread meanwhile continuing to be carried around the needle under' snug tension until the needle draws it down through the preceedino' loop, as illustrated in Fig. 9, when the arm 22 will ride out of the cam recess, leaving' the arln 22 in its normal position.

llfleantime the arm B-lhas been passing the recess in the cam collar 36, lirst braking' the rcel 6 and tllell gradually releasing,r the brake, until, preferably as the arm 22 clears the recess in cam collar 20, the arm 3% will clear the recess ill collar 8G, freeing the reel 6 to yieldthe thread under normal tension, until the take-up operation is repeated in the next stitch cycle.

Thus the tension on the thread is Varied so as to correspond to the requirements of accu ate work in the various phases of the stitch cycle, and an eren and accurate output is secured from the machine with a minimum of detect-s from. dropped stitches or other similar errors in the stitching.

rlhe success of this arrangement lies, in

principle, in suullbing;` up the thread at the propo ,t nt to insure its catching` under the barb ol' the needle, and in then reestablishing; the normal tension, as already explained.

r)The ll'lcchanisnl illustrated and described selected a typical example of the application of my invention, but not as all er;- clusive form of embodiment thereof. VFor it is obvious that details of construction mayi be modified, as by the use of mechanical equivalents or the like, without departing from the spirit of my invention or the scope of the claims.

l-laif'ingr thus described nly invention, what I claim and desire o secure by Letters filaten t of the llnited tltates, ist* i. lil a sewing lllaclline, embodying loop stitch forming means including,r a barbed needle, the colnljlination of rotatable thread carrvingi` and supplying; means, automatic means for temporarily and positively a1'- rcsting' and holding' the thread carrying' and sul'lplying mains once during eacll stitch cycle, so as :o permit the release of the threath and means for positively increasing the 'tension on 'the thread after the carrying and sui'lplying' means has been arrested and the loop llas been cast around the needle lelow the barb, whereby the loop will be snuegled under the barb for each stitch.

ln a sewing machine, embodying loop stitch forming means including.,r a barbed needl l, the combination ot a rotatable thread supplying; reel.. positive reel braking` means and periodically acting' controlling' mechanism therefor, and automatic, periodically actuated tension .'arying means, the periodic actions of the braking' means and tension mea cooperatingT 'to snug' the thread under the needle barb in the formation of each stitch.

ln a sewing' u'lachine, embodying` loop stitch forming; means including a barbed needle, the combination of a rotatable thread supplying reel, positive reel stopping' means, includina` a ratchet and pawl, and periodically acting; controlling' mechanism therefor, and automatic, periodically actuated tension varying' means, the periodic actions of the braking,` means and tension means cooperating; to snug? the thread under the needle barb in the formation ol each stitch.

4t. ln a sewing' machine, embodyina' loop stitch forming' means including a barbed needle, the combination of a rotatable tllrald supplying reel, p sitive reel braking` means and periodically acting cam governed controlling,` mechanism therefor, and automatic, periodically actuated canl governed tension varying' means, the periodic actions of the braking means and tension means cooperating` to snug' the thread under the needle barb in the formation of each stitch.

JOSEPH A. GROEBLI.

l Uli 

